1. Field of the Invention
The present invention relates generally to beverage dispensers, and in particular to beverage dispensers designed for ease of assembly and maintenance and that provide for efficient cooling.
2. Background
Beverage dispensers are well known in the art and are generally of the post-mix or pre-mix variety. As is known, post-mix dispensers mix carbonated or flat water at a particular ratio with a concentrated syrup to produce a finished drink. Pre-mix dispensers simply dispense a finished drink that has been previously produced and filled into pre-mix containers at a beverage bottling facility. Such dispensers include means for cooling the beverage or the separate beverage constituents and a plurality of valves for dispensing thereof. In the case of electrically cooled post-mix dispensers, a refrigeration system including a compressor, condenser and evaporator are typically used to cool a water bath. The evaporator is positioned in the water bath and cooled to from a layer of ice or ice bank thereon to provide for a cooling reserve. The beverage constituents flow through heat exchange lines retained in the water bath for cooling thereof as they flow to the dispensing valves. The compressor and condenser and associated electrical components are generally secured by screws or bolts to a plate that is itself fastened to the top of the water bath tank.
A problem with prior art dispensers of the type described above concerns the time required for assembly thereof. Assembly times can exceed eight hours per dispenser resulting in relatively high labor costs. A large part of the labor input concerns the securing together of the various parts, generally using fastening means such as screws manipulated either manually, with hand tools, or with the use of power tools. It would be highly desirable to reduce or eliminate such time consuming means of fastening. However, the substitute means for attaching must have or approximate the strength, flexibility of application and durability of screw attachment approaches.
A further problem concerns the exterior surfaces of such dispensers. As is well known, beverage dispensers come in various sizes depending upon the numbers of individual valves provided by the particular machine and the volume of beverage that the dispenser is designed to handle at peak dispense times. With respect to varying the number of valves, the dispenser gets wider in a horizontal direction with an increase in the number thereof as the valves are installed side-by-side horizontally. Prior art dispensers have exteriors that include sheet metal panels that do not easily provide for any commonality of assembly of such exterior components between dispensers of various sizes. Accordingly it would be desirable to have the various exterior surfaces of a beverage dispenser consist of components that can provide for such commonality. It would also be desirable for such components to be able to be assembled without the need of hand or power tools.
An additional problem with beverage dispensers concerns the ability of the exterior surfaces thereof to provide for point of purchase advertising thereon in a way that uses the maximum available surface area thereof. Many beverage dispensers are located in areas that are readily viewable by the consuming public. While this is obviously the case for machines of the xe2x80x9cself-servexe2x80x9d variety that are operated by the individual consumer, this is also often the case for machines that are operated by service personnel. It has long been known to use the exterior surface of such dispensers for the placement thereon of advertisements as an enticement to consumers to purchase a beverage and also to inform the public as to the brand and flavors of products being dispensed. Unfortunately, changing such advertising artwork is not easily done. Especially, where the advertising graphics are applied directly to, for example, an exterior sheet metal housing of the dispenser, which housing is not made to be easily removed from the dispenser and/or which graphics are not easily removed from the housing surface. In dispensers utilizing roto-molded plastic ice bath tanks, the plastic exterior of such tanks forms a portion of the exterior surface of the dispenser. Unfortunately, such tank surfaces are not amenable to the placement thereon of advertising artwork due to surface irregularities inherent in the roto-molding process. Thus, approximately 50% of the exterior surfaces of such dispensers are not available for advertising display. Accordingly, it would be very desirable to have a dispenser that provides for the maximum utilization of the exterior surface area thereof for the purpose of advertising display. It would also be desirable to have a dispenser that can be easily converted from opaque graphic display to one utilizing a back-lit transparency.
A further problem with beverage dispensers concerns the efficiency of operation of the refrigeration system and the ice bank. As stated above, many such dispensers utilize an ice bath for retaining the evaporator for forming a volume of ice thereon. This ice bank provides for a cooling reserve that can be used during times of high cooling demand when beverages are being dispensed at a high rate. Thus, the refrigeration system does not have to be sized to provide for all of the cooling at such peak dispense times. However, a problem with such cooling strategy is the fact that ice is a relatively good insulator. Thus, the thicker the ice that forms on the evaporator the more the evaporator is insulated from cooling the bath water, resulting in less efficient cooling thereof. As a result thereof, there is a tradeoff between amount of cooling reserve and efficiency of operation of the evaporator. A further problem concerns the fact that as the ice bank grows on the evaporator tubes and bridges there between, less surface area of the formed ice is in thermal contact with the water bath. The less efficient cooling that occurs as a result of ice insulating the evaporator and reduction in the surface area of the ice bank reduces the cooling ability of the water bath with respect to heat exchange between it and the beverage constituent coils. Thus, beverage is not able to be cooled as efficiently as possible. Accordingly, it would be highly desirable to have an ice bank/evaporator structure and management strategy that maximizes heat exchange between the water in the water bath tank, the ice bank and the liquid beverage components in the product coils.
It is known in the prior art to use syrup pumps to move the beverage syrup from sources thereof to the post-mix valves. And, it is known to have the pumps located either exterior of the dispenser or located there within. However, the dispenser must generally be configured one way or the other at the factory. It would be desirable to have a dispenser that could be field configurable between an internal or external syrup pump configuration.
The present invention is a beverage dispenser that can be assembled virtually entirely by hand without the need for hand or power tools. In addition, a novel approach to forming the exterior surfaces thereof is provided. A new structure and method of ice bank construction and control is also shown.
The dispenser herein includes an ice bath tank for retaining a volume of water and in which an evaporator is positioned along with a carbonator and a plurality of water and syrup heat exchange tubes. The water bath tank includes four bottom legs having tabs that provide for sliding retaining cooperation with corresponding slots located in a dispenser base. A refrigeration deck includes slots for receiving tabs extending upward from the top end of the water bath. The water bath tabs include holes for cooperating with metal pins that insert therein for retaining the refrigeration deck in place on top of the water bath.
A rear panel is secured to the base by a snap fit therein and by slots receiving mounting pins extending from a top perimeter surface of the water bath tank. Two side panels are then slideably engaged with the base, the water bath tank and the rear panel. A top louvered panel is then slideably engaged with the side panels and the rear panel followed by the securing of a front panel to the side panels and the top panel. A single screw is used to secure the top panel to the front panel thereby retaining all the panels in place.
A refrigeration deck includes a plurality of slots for receiving therein tabs extending upward from a perimeter edge of the water bath tank. When the tabs are inserted therein, removable clips provide for retaining the deck to the top of the water bath tank. An evaporator coil is suspended from and below the refrigeration deck for positioning thereof in the water bath tank. The water bath tank retains a carbonator, a plurality of syrup cooling coils and a water cooling coil. The water coil is situated along a bottom surface of the water bath tank. A baffle plate is secured to a top surface of the water cooling coil pack and includes a central hole there through and angled edges around a perimeter thereof. A water pump and a compressor are releasably secured to a top surface of the deck by a clip and pin attachment. A condenser is also quickly removably secured to the top of the refrigeration deck by a shoulder and pin securing system. An agitator is quickly removably secured to the deck and drives a propeller secured to a drive shaft that extends into the water bath.
Those of skill will understand that the present invention can be assembled wherein the water bath tank can be secured to the base after which the syrup coils, carbonator, water coil pack and baffle can be assembled together and dropped into the water bath tank. Beverage dispensing valves and their connection points are fluidly connected to the water and syrup coils and are secured to and supported by a front portion of the water bath tank. The refrigeration deck includes a deck plate having releasably secured to a top surface thereof various components including the evaporator, condenser, compressor and agitator. An evaporator is secured to a bottom surface of the deck plate and suspended therefrom. The completed refrigeration deck is then lowered onto the water bath tank wherein it rests on a top perimeter edge thereof with the evaporator positioned within the interior volume thereof. Slots in the deck plate receive corresponding upright tabs extending from the top perimeter edge of the water bath tank for proper positioning fitting of the deck and tank together. Clips are attached to the water bath tank tabs for retaining the deck and tank together. The exterior panels can then be secured to the base and water bath tank in the manner and sequence as above described completing the assembly thereof. It can be appreciated by those of skill that the present invention provides for a greatly improved ease of assembly over prior art dispensers that rely essentially solely on screw fasteners. As a result thereof, the time of assembly is significantly reduced.
It can also be understood that having removable exterior plastic molded panels substantially reduces the cost of the dispenser compared to dispensers having an exterior housing made of stainless steel sheet metal. The molded plastic panels also lend themselves to greater design freedom with respect to the exterior configuration and appearance of the dispenser of the present invention as opposed to dispensers having a sheet metal exterior. In addition, substantially the entire expanse of the surface area of the back and side panels can be used for point of purchase graphics. Moreover, the side and back panels are not interrupted by seams or other discontinuities that would detract from the advertising graphics. It can also be appreciated that the side panels can be easily and inexpensively interchanged with other equivalent panels having new or different advertising artwork. The front panel can also be used in that regard and can be used to house a lighting fixture to provide for a back-lighted graphics transparency.
The exterior panel approach also permits a certain degree of modularity with respect to dispensers having different numbers of valves. It can be understood that the same size side panels can be used in a family of dispensers where the change in size is only with respect to side to side width, not height and front to rear depth.
Those of skill will understand that there are two primary beat transfer mechanisms which occur to create the efficient cooling of syrup and water contained inside the product coils. The first mechanism is the heat transfer between the ice, generally at a temperature of 32 xc2x0 F., and the bath water, generally at a slightly warmer temperature, typically 32-36 xc2x0 F. The second mechanism is heat transfer between the bath water and the syrup and water contained in the product tubes. The syrup and water are typically chilled from on entering temperature of 75-90 xc2x0 F. to a leaving temperature slightly above the bath temperature, e.g. 38 xc2x0 F. A limiting heat transfer factor is the heat transfer between the water and the ice. In order to enhance that heat transfer, the present invention uses a specifically designed evaporator wherein a thin ice approach is provided for. Ice grows in annular rings around the individual evaporator tubes, and the tubes are spaced at a distance great enough to discourage ice from bridging there between and instead grow in an annular fashion there around. This approach provides for maximum ice surface area exposed to the bath water. Ice thickness is also controlled to a minimum, resulting in a minimum resistance to heat transfer between the bath water and the refrigerant flowing inside the evaporator tubes.
In order to further maximize heat transfer to the product coils it is known to agitate the water. In the present invention a novel water directing or flow baffle is used in conjunction with an agitator. In the center of the baffle plate is a hole and along its edges are vanes that are angled upward towards the ice bank. Also, an essential aspect of the water bath design employs the placement of product coils below the ice bank at the bottom of the water bath with the baffle horizontally secured to a top surface of these bottom product coils. An agitator impeller is placed near the geometric center of the bath and the center hole of the flow baffle for creating a downward circulation of the water through the inside of the ice bank and toward the flow, baffle. The special geometry of the flow baffle causes a portion of the downward flowing water to be turned around and directed upward against the ice bank. The remainder of the downward flow is directed through the center hole and into the product coils. The flow baffle provides the ability to increase the heat transfer coefficient between the water and the ice. The amount of water that is turned upward and directed at the ice may be controlled through adjustment of the overall dimensions of the plate and the center hole size. Furthermore the upward flow direction may be optimized by adjustment of the geometry of the flow vanes. In general, as more water is directed upward against the ice, the heat transfer coefficient increases and the bath water temperature decreases and more closely approaches the ice temperature of 32 xc2x0 F. While more flow is directed upward against the ice, less flow is available to the product coils in the bottom of the water bath. However, this lower flow was not found to greatly reduce the heat transfer between the bath water and the product coils. It was found that the water flow over the product coils may be reduced to a relatively low level before a reduction in heat transfer occurs. The baffle approach provides the flexibility to find the optimal balance, given the size parameters of the particular dispenser, between the proportion of the total agitated downward flow that is returned to the ice bank and that is directed to the product coils. Thus, adjustment of hole size and vane angle can be understood to serve as an efficient and flexible means to optimally design the water bath flow parameters to provide highest level heat transfer in water baths of different sizes and shapes. As a result thereof, the dispenser of the present invention provides for drinks that are significantly colder than can be obtained in conventional dispensing systems.
The present invention includes a merchandising cover that permits for quick low cost conversion from an opaque display to one utilizing a back-lit transparency. A light power unit is releasably securable to a back surface of the merchandising cover after the cover has been detached from the dispenser. A reflective sheet metal sheet is retained within an internal area of the merchandising cover and serves to receive snap fitting light sockets from the power unit. A pre-existing power socket is positioned behind the merchandising cover to which the power unit is connected. The merchandising cover is then re-attached to the dispenser and a transparency is releasable secured to an external perimeter edge of the cover. Thus, the present invention provides for a xe2x80x9cplug and playxe2x80x9d low cost means for quickly and easily converting to a desirable lighted graphics display.
The present invention also provides for the option of having syrup pumps located therein. The molded plastic base is securable to a pump retaining box positioned there below. The box includes a plurality of syrup pumps secured to a drawer therein. The drawer is slideably engaged with the box and is accessible by a removable plate.
After removal of the plate, the drawer can be accessed and slid out of the box for facilitating repair or replacement of the pumps. By having a separate box securable to the base thereof, the dispenser can be easily retrofitted in the field with optional xe2x80x9cinternalxe2x80x9d syrup pumps where that configuration is desired.